One skilled in the art is familiar with many methods for controlling cooking processes. The reason for this is that, depending on the type of food to be cooked and on the size and amount of food, a different cooking process is often required to obtain optimal results in each specific case. The same is also normally true for the reconstitution of precooked food. Although precooked food items can be reconstituted by using a preset timing program to control the steam production system or by using a single- or multi-stage timing program to control the humidity, uncontrolled condensation, leading to the formation of undesirable puddles, still occurs frequently. Another frequent occurrence is that the food to be cooked dries out as a result of insufficient humidity. The reason for these problems is that the temperature and humidity conditions prescribed by the reconstitution program are not oriented around the actual conditions present during the course of the cooking process.
DE 198 43 500 A1 describes a method for operating a household appliance for nonpressurized steam-cooking, in which the amount of steam is regulated as a function of a reference value TD on the basis of the temperature value detected by a temperature sensor. The reference temperature value TD is obtained by heating water in the steam generator of the household appliance until the temperature in the cooking space stops increasing. This reference value is preferably determined while the cooking space is empty, that is, before or after it is washed. By means of the procedure described in DE 198 43 500 A1, it is said that it is possible to adjust the variables precisely to the ambient conditions even if the temperature measured in the cooking space deviates from the actual temperature as a result of, for example, the manufacturing tolerances of the temperature sensor. In particular, the idea is to prevent the steam temperature from being set too low, because this has a negative effect on the cooking times and thus on the cooking results. Another reason why it is necessary to prevent the measured temperature from dropping too low is that the steam generator would otherwise keep operating continuously. The method according to DE 198 43 500 A1 is intended to eliminate these disadvantages. Nevertheless, the method of DE 198 43 500 A1 still does not ensure that uncontrolled condensation, leading to the formation of puddles and thus to a permanent impairment to the quality of the food, will not occur during the reconstitution of precooked food or during the cooling process after the completion of cooking.
A method for controlling a cooking process in the cooking space of a cooking appliance as a function of a dew point is known from WO 01/59370 A1, according to which the climate in the cooking space is controlled as a function of climate parameters (temperature, humidity, and pressure), which are determined by sensors. Once the dew point is determined, the steam pressure can be selected, and by adjusting this pressure with precision, the food being cooked can be prevented from drying out.
DE 43 41 410 A1 describes a baking and roasting oven with an electrically heated cooking space, a heated steam generator for the cooking space, and a hot-air blower, where a measuring device, which is designed as a humidity sensor and forms part of a measurement evaluation unit, is installed in the area of the cooking space to detect the steam concentration. A condensate trap with a temperature sensor is also installed in the cooking space, this trap being connected downstream from a cooling unit. The climate of the cooking space can be controlled automatically by the measurement and evaluation of the concentration of steam in the cooking space.
EP 0 567 813 A1 describes an arrangement for measuring the amount of moisture present in a cooking appliance. This arrangement comprises a reference body with two sides, one of which is exposed to the climate of the cooking space, whereas the other is cooled. By measuring the temperature on both sides and the temperature of the cooking space, it is possible to determine the dew point inside the cooking space atmosphere. The relative humidity in the cooking space can then be derived from the determined dew point on the basis of a set of stored curves.
U.S. Pat. No. 5,780,818 discloses a method for controlling a cooking process with hot air and steam, where phase transitions in the food being cooked or in the cooking space climate are derived from the course of the temperature measured at certain points inside the cooking space. Then, on the basis of these phase transitions, it can be concluded when the steam content in the cooking space climate should be lowered to a value below the saturation value.
A method for controlling a cooking process as a function of at least two temperature values acquired from a cooking process sensor, which can be inserted at least part of the way into the food item being cooked, is known from DE 199 45 021 A1. Via the thermokinetics of the detected temperature values, specific parameters of the food and/or of the cooking appliance are determined, and the specific food and/or appliance parameters thus determined are used to control the cooking process.
Finally, EP 0 386 862 A1 discloses a cooking appliance with a cooking space and a device for introducing water in liquid form or as steam into the cooking space. In addition, a device for discharging moisture from the cooking space, at least one humidity sensor in the cooking space, and an automatic controller, which actuates the device for discharging moisture from the cooking space and/or the device for introducing water, are also provided.